An organic electroluminescence device (hereinafter the term “electroluminescence” is often abbreviated as “EL”) is a self-emission device utilizing the principle that a fluorescent compound emits light by the recombination energy of holes injected from an anode and electrons injected from a cathode when an electric field is impressed.
An organic EL device has made a remarkable progress. In addition, since an organic EL device has characteristics such as low voltage driving, high luminance, variety in emission wavelength, high response and capability of fabricating a thin and lightweight emitting device, its application to a wide range of fields is expected.
Emission materials used in an organic EL device have conventionally been studied actively since they influence largely the color of light emitted by a device or on emission life.
As the emission material, a chelate complex such as tris(8-quinolinolato)aluminum complex, a coumalin derivative, a tetraphenylbutadiene derivative, a bisstyrylarylene derivative and an oxadiazole derivative are known. By using such emission materials, emission in a visible range from blue to red can be obtained.
Use of a phosphorescent compound as an emission material for utilizing triplet energy for emission has been studied. For example, it is known that an organic EL device using an iridium complex as an emission material exhibits a high luminous efficiency.
An organic EL device using polyphenylene vinylene (PPV) as a conjugated polymer is known. In this device, PPV is applied and formed into a single film and this device is confirmed to emit light.
Patent Document 1 discloses an organic EL device using a layer containing 9,10-di-(2-naphthyl)anthracene derivative as an organic layer. Patent Documents 2 and 3 disclose an organic EL device using a layer containing a phenanthrene derivative as an emitting layer.
Patent Document 1: U.S. Pat. No. 5,935,721
Patent Document 2: U.S. Patent application publication No. 2004/076853
Patent Document 3: JP-A-2006-151844
An object of the invention is to provide an organic material which is suitable for use as a material of an organic EL device.